Radio system



ai? 26 1927' y p. F. sHuEY k RADIO SYSTEM Filedl Nov. l0. 1922 2 Sheets-Sheet 1 nml ` llllllllll'f 1, 31,05 July 26,1921. RRSHUEY 6 s RADIO SYSTEM Filed Nov. l0. 1922 1 2 Sheaets-Sheeat` 2 WITNESS 5 T23 L 49 l mnnl/@nigh 1jr 79W' l Patented July 26, 1927.

UNITED STATES PAUL F. SHUEY, F PITTSBURGH, PENNSYLVANIA.

RADIO SYSTEM.

Application led November 10, 1922. Serial No. `600,057.

My invention relates broadly to radio systems, and more particularly to radio receiving systems employing a plurality of telephone receivers or loud speakers or both..

The object of this invention is to provlde a radio receiving apparatus, such, for eX- ample, asa standard receiving set, with an indefinite number of telephone receivers or loud speakers or both in excess of the number hitherto regarded as satisfactory or feasible. By my invention I have successfully used considerably more than one hundred telephone receivers on a single standard radio receiving set. My improved system is Well adapted to furnish individual beds, rooms, apartments and the like in hospitals, hotels or apartment houses or the like with radio service Jfrom a single receiving set. This object may be carried out by many modifications of my system, the accompanying drawings showing only a few of such modifications.

Referring to the accompanying drawings Fig. 1 is a diagram showing a portion of a radio receiving system containing one embodiment of my invention. Figs. 2, 3 and 4 are diagrams showing modifications of portions of Fig. 1.

Referring first to Fig. 1, 1 desi ates the final electron tube, such as the fina amplifying tube, of a radio receiving set, this tube having the usual plate 2, the filament 3, and the grid 4, the connections of the latter two not being shown, as they are well known.

' I show the A battery 5 and the B battery 6 connected in series, the A battery having the leads 7 and 8 for furnishing current for heatin the filaments of the detector and ampliifing tubes in a manner well known, the point 9 being a connecting point between the two batteries.

10 is an amplifying transformer of the power or other type for additional ampliication. Its primary winding 11 has one terminal connected to the positive end of the B battery and its other terminal connected by one branch wire 12 to the plate 2 and by another branch 13 to one terminal of the primary winding 14 o the transformer 15, the latter branch containing the condenser 16. The remaining terminal of the primary winding 14 is connected by the wire 17 in commonwith one terminal 0f the primary winding 18 of the transformer 19 by the wire 20 which may b9 .C-Oniled iQ the positive pole otthe B battery 6 at 21, to .the point 9 at 22, or to the negative pole of the A battery 5 at 23 either directly or throu h the electromagnetic switch 24, operated y the winding having one end connected to the last named battery pole and its remain-.

33 is a choke coil connected'at one end to a point between the condenser 29 and the plate 30, and atthe other end to a point between'- the battery -6 and the transformer winding 11. 1

The secondary winding 34 of the transi former 15 has its terminals connected by the wires 35 and 36 to the opposite ends of a groupr37 of telephone receivers 38. The group 39 of receivers 38 may be connected across the wires 35 and 36 in parallel with the group 37. VThe condenser 40 may be -ineluded in the wire 35 to prevent the flow of direct current, if any` on the wire, or to vary the output impedance to the receivers; and the telephone transmitter or microphone 41 may be connected to the negativev pole of the battery 5 and to the wire 35, as'shown, so that the operator of the radio set may make announcements to those listening in at any of the receivers 38.

The secondary winding 42v of thetransformer 19 has one terminal connected through the condenser 43 to one terminal of each of the loud speakers 44,-the otherloud speaker terminals being connected to the rings 45 of the jacks 28. The springs 46 in line with the rings 45 are connected to multiple to the wire 47 which is connected to the. 'remaining terminal of the secondary winding 42 of the transformer 19, while the vcontacts 48 carried bythe springs 46, but insulated therefrom, are connected in mul-v tiple to the wire 49 which is electrically connected to the point 9, the latter being also electrically connected by the wire 50 to the wire 36to supply current for the transmitter 41. The open circuited wires leading to the right of the jacks 28 indicates extensions for connection of additional jacks.

For best results the primary impedance of the transformer 10 equals the output irnpedance of the tube 1 or its associated circuit, and the Secondary impedance of the 'transformer' 15 or ofthe transformerfli-'and 001'1118115614 40- equals the'impedance' `of the' circuit or circuits which contain the translating. device's, comprisin tions, as'fseries, par allel2 orfseries-parallel,

that ,the impede-noe theyl'iifisert`- inthe?` output Q in the sections 515'Y of iithefgr @quali'rfpproxiriat the? Secilfler'y; impedance.v Accordingly, somefof-"the receivers may be. vpli'iced `inseries'parallel,relation, as psa? and se, purallelrclation, h sectionsmay be and 4some maybe plat connected iny series- .inieachzgrup, 'as shOWn,

' and" the lgroup/stpv or theseticns m befpiadeal*parallelerpartly el methods "of arranging the 'receivers-ic* et .transformer lfaiid vthen 'candecide upony a andarrangement of the` receivers giveth'e' best results. 'O t course,

results more-1er less approximating those obu vtainablej by'balancing-the impedances as dei also placed in parallel with the first and sec-1 This invention satisfactory` or The laci one receiver across the termina s of t c secondary of atransformerl inserts in the secondary circuit a certain `1m- -pedance` It a" second receiver be placed in series with the first the insertedimpedance is doubled, but if the second -receiver is placed inparallel with the first the inserted impedance is halved. Ii, however, the two receivers be connected in series across the secondary terminals and additional third and fourth receivers connected in series be ond receivers, the impedance due to the receivers will lbe approximately the firstreceiver when it` was employed alone. The 'impedance due toene receiver can be approximated by making the number of receivers in each series and-the number of series arranged inarallel equal to the nare root of the num r of receivers used.

ere the number of receivers are not perfeet squares, can be approximated. The rinciple of balancing the impedance by o setting inserted serieselements by insertedparallel elements,

fr the" receivers or;l ilher impedance of acedf`iii "parallel,4 asgshown, y

'1in series, and gcd; inset-ies,1 'orfparti `f parallelQ 1 l The f thefforegoing description are merelylllgisttatds' v egbest results-,from thel receivers [T e person skilled in the art can lreadily "determiiiefrom the requirements lo1? VVan installation the characteristics of the lbe secured 'when the balancing' rtransform that due Ato the arrangement just defined v arrangements. v e design of the transformer, or of the transformer and condenser maybe so chosen that the secondary imped ance approximates a parallel or a series or combined groupingr of a certainiiumber of receivers. Then additional receivers may be added by 'grouping them to suit the transformer impedance.

to :include `telephone receivers, or loud speakers, or both.

The loud speakers l44 may be connected in circuitby inserting a plug in any of the jacksf28, each plug being, of course, operatively connectedto one of the loud speakers 44 in the usual manner, not shown. The insertion of a plug into a jack directly connects in the usual ymanner a ring 45 and a spring 46 in serieswith the loud speaker, and indirectly connects a contact 48 to a In the claims the word receivers is yused or vice versa, maly be utilized in numerous spring 27, thelatter connection placing the Amagnet winding 25'in circuit with the batteiy4 ..5` through the wires 26 and 49. Thev ','current inthe winding 25 causes the switch '24 to close automatically the circuit of the wires 7 and/8 for heating the various ampliyingl and detector tubes.' Of course, the

loud speakers could be left in permanent operating `circuit,-if desired, thereby allowin the switch 24and its o erating circuit to e left oi, the wire 8 then eing connected to the battery 5 directly or as desired.

In computing the impedance desired in .the outputl circuit 'of thesecondary 42 of the transformer 19, the same considerations will obtain-as for the output circuit of the transformenl.

For any step fof amplification, the .system mayor maylnot lemploy -the high impedance winding orchoke 33 to by-pass the batte current to v`- plate 30, in conjunction Wit the condenset29 to allow the audio-frequency current toi'pfsathrough the primary ofthe and through the plate If this cholref-arirl'v condenser are not! used the transformer primar 18 is connected in serics with the plate 30 o ,the tube 31.` 'If-'they are used, the terminal ofthe primary winding `18farthest#from the plate 30may be conf nected by the wire 201:0 either terminal of either bat-teryy' or 6. Theprimar as' .11, of one or more of' the 'amplifyingtransfcrmers of the set may be used as-an audiofrequency'choisie to by-pa'ss a portion of the audio current, as between theplate' 2 and the primary 14,f.the remainder ofthe current assing 'through the amplifying transormer, as 10, for further amplification, as

by the transformer 19, when both receivers- 38 and loud speakers 44 'are to be used.

The additional amplification required for the loud speaker portion of the system may be obtained as just described or by additional ampliier units of ordinary or power 'isc amplification type, by placing the primary, as 11, of the amplifying transformer in series with the primary, as 14, of the telephone receiver system, as shown in Fig. 2.

Referring now toFig, 3, I may use, as an alternate circuit when the choke 33 and the condenser 29 are used, the Uroup of receivers 38 or loud speakers 44, which may be connected in series with the primary, as 18, of the receiver system transformer in such a manner that the polarity of the secondary Winding 42 is such that its .effectl on the receivers is additive to that impressedY directly on them through the primary Winding 18. The transmitter 41 may be used for the purpose for which it is used in Fig. 1.

When it is desired to use only a few loud speakers 44 with receivers 38, the amplifying means shown for the loud speakers are omitted or disconnected from the system, an at the points 54 and 55, and the wires to the right of these points are respectively connected to the points 56 and 57,'respectively in the Wire 17, the portion of the latter between the latter points being omitted or open circuited, I 'show in Fig. 4 the modification just described. The separate sections 51 and 52 or their equivalents maybe placed in different wards,-wings, or sections of hospitals or other buildings, or `indifferent buildings. The chances are that the persons in the several sections will act similarly, so that the system will continue to be in fairly good balance, although the nurnber of receivers may be constantly changing.

. cuit therewith,

.different portion of I claim- 1. In a radio receiving system a 4relatively large number of receiving elements, and a transformer having the said receivers in cirthe receivers being grouped 1n series and parallel relations to make the impedance they impose in the circuit approximate that of the secondary of the transformer. 2. In a signal-reproducing system adapted to serve a plurality of persons, a. plurality of` groups of translating devices, each group being located in a place frequented by a said' plurality of persons, a line connecting said groups in parallel, and a signal-delivering device connected Vto said line, the places for the groups being so selected that the probability of the numin the respective ber of translatingdevices groups in use at the same time being approximately equal will be great.

3. In a vacuum-tube, signal-reproducing system, a vacuum-tube amplifier, translating devices connected to the output thereof, other translating devices requiring greater energy than the first mentioned translating devices, a second amplifier having its input connected to the output of the first mentioned amplifier and its output to said other translating devices and means actuated upon translating devices for rendering said second amplifier active.

In testimony whereof, I afiix my signature.-

PAUL F. SHUEY.

a5 f the closing of the connection to said other I 

